could we have a setup which allowed IP for only certain countries.

I know that IP addresses or at least ipv4 addresses are geographically located so I was wondering if it was possible to block all IP from say North Korea, China, etc.

Even better would be that I know I wont have any staff member connecting from any countries other than Europe and USA. So I would like to blacklist all other IP's. This would at least reduce my exposure to hackers.